Mitigation of power system blackout by blocking zone3 of minimum distance relays

Electric power systems are complex systems with Self-Organized Criticality (SOC) that are commonly run near their operational limits. In these systems, blackout is unavoidable. One of the main causes for some of the recent blackouts around the world was distance relay hidden failure. In this paper a novel approach is proposed to prevent the undesirable contribution of distance relay on cascading failures and blackouts by inactivating zone3 of minimum number of distance relays. The proposed approach is demonstrated on the New England 39-bus system and detailed simulation studies carried out to examine the validity and effectiveness of the proposed method.